Is there a way to film horizontally (16:9) on a vertical phone?

Here's what I mean by this. I would hold my phone vertically to record, and instead of it recording vertically, I want it to record horizontally. Is there any way at all to make a phone do this? If it helps, I have a rooted Verizon LG G3 (VS985) running CyanogenMod 12.1.